1. Field of the Invention
This invention relates to an imaging apparatus for performing signal processing depending on the operational modes.
2. Description of the Related Art
A digital still camera retrieves image data obtained by a CCD image sensor into a DRAM or a flash memory and subsequently transfers the image data to a so-called personal computer or the like. A major proportion of this type of the digital still camera has hitherto been of the type coping with the video graphics array (VGA) system.
Referring for example to FIG. 1, this digital still camera 200 includes a CCD image sensor 201 for generating image signals, an input processing/image processing circuit 202, a memory controller 203 for reading and writing image data, an output processing circuit 204 for conversion to an output image of a pre-set system, a finder 205 for displaying the state of an object at the time of image shooting, a recording unit 207 for recording compressed image data over a CPU bus 206 and a compression/expansion circuit 208 for compressing/expanding image data. The digital still camera 200 also includes a memory 209, formed by, for example, a DRAM, and a CPU 210 for controlling the overall device.
Before starting the image shooting of an object, the user has to confirm an object image displayed on the finder 205. This state is termed a finder mode. At this time, the CCD image sensor 201 sends image signals obtained on photoelectric conversion to the input processing/image processing circuit 202. The input processing/image processing circuit 202 performs the correlated dual sampling processing on the image signals to digitize the image signals. The input processing/image processing circuit 202 then performs pre-set signal processing, such as gamma correction, knee processing or camera processing and routes the processed image signals to the memory controller 203. The memory controller 203 then is responsive to the control by the CPU 210 to send the image data from the input processing/image processing circuit 202 to the output processing circuit 204. The output processing circuit 204 encodes image data in accordance with, for example, the National Television System Committee (NTSC) system, and analogizes the encoded image data to route the resulting analog data to the finder 205. This allows the object as an object of image shooting to be indicated on the finder 205.
On the other hand, if the user pushes a shutter button, not shown, to shift to the recording mode, the memory controller 203 causes the image data furnished from the input processing/image processing circuit 202 to be written in the memory 209. The CPU 210 causes the image data to be read out from the memory 209 and compresses the image data from the recording unit 207in the compression/expansion circuit 208 with compression in accordance with, for example, the Joint photographic Experts Group (JPEG) system to record the compressed image data in the recording unit 207.
If the user performs pre-set processing to shift to the reproducing mode, the CPU 210 causes image data to be read out from the recording unit 207 to cause the image data to be expanded in JPEG system in the compression/expansion circuit 208 to route the resulting data via memory controller 203 and output processing circuit 204 to the finder 205. This causes the as-shot image to be displayed on the finder 205.
In keeping up with recent outstanding technical progress in the CCD image sensor, the resolution of image data is nearly surpassing 1,000,000 pixels. On the other hand, it may be feared that the digital still camera of the above-described structure cannot sufficiently cope with the image data exceeding 1,000,000 pixels.
If, for example, the CCD image sensor 201 outputs image signals of high resolution in the finder mode, the input processing/image processing circuit 202, memory controller 203 or the output processing circuit 204 cannot process image data in real-time, such that an image of the object is displayed on the finder 205 in a frame-skipping fashion. This incurs an inconvenience in shooting an image of object even if the object makes the slightest movement.
In the recording mode, since in which only multi-pixel image data is recorded in the recording unit 207, it is unnecessary to perform the processing in e.g., the input processing/image processing circuit 202.
That is, in the digital still camera 200, since the pre-set signal processing is performed on e.g., the input processing/image processing circuit 202 without regard to the operational mode, the signal processing has not necessarily been efficient insofar as the entire apparatus is concerned.
It is therefore an object of the present invention to provide an imaging apparatus that is able to perform efficient signal processing depending on the operational mode.
In another aspect, the present invention provides a controlling method for a signal processing apparatus adapted for transmitting/receiving image data between a plurality of signal processing means and storage means for storing image data, the signal processing means being adapted for processing the image data in a pre-set fashion and for outputting to the control means a request signal for demanding furnishment of the image data for signal processing or demanding the outputting of the processed image data. The controlling method includes selecting, on furnishment of the request signal from the plural signal processing means, one or more of the signal processing means which has outputted the request signal, and furnishing the image data read out from the storage means to the selected signal processing means or writing the image data outputted by the selected signal processing means in the storage means.
In still another aspect, the present invention provides an imaging apparatus including imaging means, storage means for transiently storing image data from the imaging means, control means for controlling the writing/readout of the image data for the storage means, a plurality of signal processing means for processing the image data in a pre-set fashion and for outputting to the control means a request signal for demanding furnishment of the image data for signal processing or demanding the outputting of the processed image data, and outputting means for outputting image data processed by the signal processing means. The control means manages control on furnishment of the request signal to select one or more of the signal processing means which has outputted the request signal to furnish the image data read out from the storage means to the selected signal processing means or to write the image data outputted by the selected signal processing means in the storage means.
In yet another aspect, the present invention provides a recording/reproducing apparatus including imaging means, input processing means for performing pre-set input processing on image data from the imaging means, display processing means for displaying image data on display means, first storage means for transiently storing the image data from the imaging means, control means for controlling the writing/readout of the image data for the first storage means, resolution converting means for converting the resolution of image data, compression/expansion means for compressing/expanding the image data and recording/reproducing controlling means for causing the compressed image data to be recorded on second storage means and for causing the image data recorded on the second storage means to be reproduced. The control means selects one or more signal processing means from the input processing means, display processing means, resolution converting means and the compression/expansion means. The control means causes the image data read out from the first storage means to be sent to the selected signal processing means or causes the image data outputted by the selected signal processing means to be written in the first storage means.
In the signal processing apparatus and the control method therefor, according to the present invention, if a request signal is sent from each signal processing means, the signal processing means which has outputted the request signal having the utmost priority in the priority order is selected. Control is then performed for supplying the image data read out from the storage means over the image data bus to the selected signal processing means, or writing the processed image data of the selected signal processing means over the image data bus to the storage means, so that efficiently signal processing will be executed in the respective signal processing means.
The present invention provides a An imaging apparatus comprising:
imaging means for generating image data based on the imaging light from an object;
memory means for storing the image data;
a plurality of signal processing means for performing pre-set signal processing on the image data;
display means for displaying an image corresponding to said image data;
a recording medium for recording the image data thereon; and
control means for performing control in a first operational mode for processing the image data from said imaging means in a pre-set fashion by the signal processing means of said plural signal processing means required to perform real-time processing to write the image data in said memory means and for reading out the processed image data from said memory means to supply the read-out image data to said display means, said control means performing control in a second operational mode for writing the image data from said imaging means in said memory means and subsequently reading out the written image data to route the read-out image data to said plural signal processing means to record the image data processed by said plural signal processing means on said recording medium.
In the first mode of the imaging apparatus, the image data from the imaging means are decimated and processed in a pre-set fashion by signal processing means required to perform real-time processing. In the second mode, multi-pixel image data are first written in the memory means. The multi-pixel image data are then read out therefrom and routed to and processed by the plural signal processing means.
More specifically, the signal processing means of the plural signal processing means which is required to perform real-time processing is caused to perform pre-set signal processing on the image data from the imaging means, in the first operational mode of the imaging apparatus, the resulting image data being then written in the memory means and the processed image data being then read out from the memory means and routed to the display means. In the second operational mode, the image data from the imaging means is written in the memory means and read out therefrom so as to be routed to the respective signal processing means for processing, with the processed image data being then recorded on the recording medium. This realizes signal processing most efficient depending on the operational mode.